c++ - Locking ostream output in macro -

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i have code proprietary logger:

#define log getstream()

where getstream returns std::ostream. user do:

log << "text";

i need thread safe avoid this:

#define end unlock(); #define log lock(); getstream() << "text" << end;

since user need add "end":

log << "text" << end;

any ideas?

remark: handle carriage return using this.

one way solve use function-style macros, incorporate locking/unlocking using c++ block , scoping:

#define log(output)               \                                \     {                             \         lockingclass lock;        \         getstream() << output;    \     } while (0)

the lockingclass (or whatever want name it) scoped lock, locks stream on construction, , unlocks in on destruction.

could used e.g.

log("hello variable " << variable);

can't use expressions containing comma though, preprocessor interpret commas argument separator macro. solved variadic macros.


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